This invention relates to a tool or cutter for cutting wood or wood products in a specific manner. Namely, the cutter of the invention is used to form what are known as raised panels wherein a panel has at the perimeter thereof a sloping or tapered portion from a raised interior portion to a thinner perimeter edge.
Raised panels may be in a variety of shapes including most often a rectangular shape, but in some instances a cathedral, round, oblong, or any other practical shape. Such panels are used, for instance, for cupboards, doors, decorative wall coverings, cabinets and furniture. Various types of wood are used, including hard and soft woods and wood products such as molded fiberboards, particle boards, and other composites of wood fibers.
The common feature of all raised panels is a generally sloping or beveled perimeter cut running generally completely around the outer edge of the panel. The slope may be in the form of a flat, inclined surface or, alternately, of a generally undulating design in various forms including bumps, ridges, depressions and convex or concave undulations. The basic feature, however, is that the thickness of the panel at the outer edge is less than the thickness of the panel at the interior raised portion.
In the prior art, a conventional cutter having radially extending wings having cutting tips thereon has been used in forms such as slopes or bevels. The cutter is of generally disk form and operates in a plane parallel to the plane of the panel. If, for instance, the panel extends in a horizontal plane, the cutter also extends in a horizontal plane and is mounted on a vertical rotating arbor. The panel is moved relative to the cutter to successfully form the bevel. Such a procedure is well known.
The profile of the cutter tip on the cutter wing forms the profile of the slope on the finished panel.
A problem in the use of such prior art cutter is that, often, the finished panel has at the intersection of the slope to the raised interior panel portion a torn edge instead of a smooth finished cut which obviously is the desired end effect. Such rough result particularly is obtained when cutting the beveled portion across the grain of the wood. A logical explanation is that the cutter tip on the wing at the extreme end which is cutting the panel at the raised portion is taking too big a bite or chip load since the cutter itself has generally but three wings, so that as the panel is removed relative to the cutter, a substantial portion must be removed from the panel between the wings.
An important factor in the construction of raised panels is the rapidity of speed at which such panels are moved through the cutter. For economic reasons, it is desirable to move such panels rapidly, causing a larger than optimum cut per revolution of the cutter. When the movement of the panel relative to the cutter is slow, to permit less of a cut per revolution of the cutter head, or between successive cuts from the tips on the wings, the panel on the sloping surfaces toward the edge ends up with a "burn" effect since there is over-cutting in that the cutter tip is taking too small a bite. Thus, there is an inherent problem in raised panel cutters in either running the panel through too slowly or too quickly.